Function ResolveModule

src/platform/linux/init.cpp:330–374

Async-signal-safe: scan /proc/self/maps via raw read() for the mapping containing `addr`. Returns its base (0 if not found); dladdr is unreliable on stripped i386.

// Async-signal-safe: scan /proc/self/maps via raw read() for the mapping containing
// `addr`. Returns its base (0 if not found); dladdr is unreliable on stripped i386.
static uintptr_t ResolveModule(uintptr_t addr, char* nameOut, size_t nameCap)
{
    if (nameCap) nameOut[0] = '\0';
    int fd = open("/proc/self/maps", O_RDONLY | O_CLOEXEC);
    if (fd < 0) return 0;
    char buf[8192];
    char line[512];
    size_t lineLen = 0;
    uintptr_t result = 0;
    ssize_t n;
    bool done = false;
    while (!done && (n = read(fd, buf, sizeof(buf))) > 0) {
        for (ssize_t i = 0; i < n; ++i) {
            char c = buf[i];
            if (c != '\n') {
                if (lineLen < sizeof(line) - 1) line[lineLen++] = c;
                continue;
            }
            line[lineLen] = '\0';
            // Parse "start-end perms ... path"
            uintptr_t start = 0, e = 0;
            const char* p = line;
            while (*p && *p != '-') { start = start * 16 + (*p <= '9' ? *p - '0' : (*p | 0x20) - 'a' + 10); ++p; }
            if (*p == '-') ++p;
            while (*p && *p != ' ') { e = e * 16 + (*p <= '9' ? *p - '0' : (*p | 0x20) - 'a' + 10); ++p; }
            if (addr >= start && addr < e) {
                // path is the last token after the final space
                const char* path = line;
                for (const char* q = line; *q; ++q) if (*q == ' ' && q[1] && q[1] != ' ') path = q + 1;
                const char* slash = path;
                for (const char* q = path; *q; ++q) if (*q == '/') slash = q + 1;
                size_t j = 0;
                if (*slash && *slash != ' ')
                    for (; slash[j] && j < nameCap - 1; ++j) nameOut[j] = slash[j];
                nameOut[j] = '\0';
                result = start;
                done = true;
                break;
            }
            lineLen = 0;
        }
    }
    close(fd);
    return result;
}

static void WriteFrame(uintptr_t retAddr)
{